1. Field of the Invention
The present invention relates to a brightness control device for controlling a light bulb module, and more particularly to a brightness control device for controlling a light bulb module to keep an even luminance of each of the light bulbs thereof, while the total consumed electric power of the light bulb module is below the maximum rated power consumption of the illumination equipment to meet the local energy ordinance.
2. Description of Related Art
In the recent years, the global energy crisis is getting more serious. Accordingly, many countries have issued various energy saving bills for dealing with such a situation. For example, the government of California in the United States is asking a strict restriction on electricity usage to the departments of the government, the enterprises, and the residents. Even more, alternating power supply in divided areas is enforced by the government due to power shortage. Currently, the United States also regulates in the law of energy the maximum rated power consumption of the related indoor illumination equipments. Each of the illumination equipments sold on the market is also required to be mounted thereon a rated power circuit breaker before leaving the factory. The rated power circuit breaker will cut out the electricity when the maximum rated power consumption is exceeded to ensure that the consumed power level of the illumination equipment meets the restrict requirement from the government. For example, according to the regulation of US energy policy, the maximum rated power consumption for the light bulb module of a normal home ceiling fixture is 190 watt. In the situation that four 50-watt light bulbs are mounted within a light bulb module of the lighting fixture, the total electric power consumption will exceed the 190-watt restrict value and thus the rated power circuit breaker set with a 190-watt normal rated power will be activated. Accordingly, the light bulb module of the lighting fixture cannot illuminate unless one of the four bulbs is removed or replaced by another light bulb consuming less electric power to meet the requirement. However, both the two methods may cause either inconvenience to the users or uneven luminance of the lighting fixture which will deeply deteriorate the lighting artistry of the entire lighting fixture.
Therefore, to control the light bulb module to illuminate evenly while meet the requirements of the energy policy in every country, a need exits for a circuitry designed for achieving foresaid objects.